The biggest difference while you are flying them is the way they handle gusts and how stable they are in the air. I had a chance to ride the two the other day and noticed quite a difference. The 2003 seem to fly farther upwind in a gust, but the 2002 seem to just pull harder. This makes it much easier to ride upwind and easier to stay in control in higher winds. This is not to say the 2002's aren't real nice. My best rides ever were on a 16m 2002.